每个C / C++程序员都应该知道的四个文件处理技巧

我们将讨论以下列出的四个文件黑客：

1. 重命名–使用C / C++重命名文件
2. 删除–使用C / C++删除文件
3. 文件大小–使用C / C++获取文件大小
4. 检查是否存在–检查C / C++中是否存在文件

// A C++ Program to demonstrate the
// four file hacks every C/C++ must know
  
// Note that we are assuming that the files
// are present in the same file as the program
// before doing the below four hacks
#include
#include
#include
  
// A Function to get the file size
unsigned long long int fileSize(const char *filename)
{
    // Open the file
    FILE *fh = fopen(filename, "rb");
    fseek(fh, 0, SEEK_END);
    unsigned long long int size = ftell(fh);
    fclose(fh);
  
    return (size);
}
  
// A Function to check if the file exists or not
bool fileExists(const char * fname)
{
    FILE *file;
    if (file = fopen(fname, "r"))
    {
        fclose(file);
        return (true);
    }
    return (false);
}
  
// Driver Program to test above functions
int main()
{
    printf("%llu Bytes\n", fileSize("Passwords.txt"));
    printf("%llu Bytes\n", fileSize("Notes.docx"));
  
    if (fileExists("OldData.txt") == true )
        printf("The File exists\n");
    else
        printf("The File doen't exist\n");
  
    rename("Videos", "English_Videos");
    rename("Songs", "English_Songs");
  
    remove("OldData.txt");
    remove("Notes.docx");
  
    if (fileExists("OldData.txt") == true )
        printf("The File exists\n");
    else
        printf("The File doesn't exist\n");
  
    return 0;
}

输出：

执行程序前的屏幕截图：

执行程序后的屏幕截图：

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